relocatable.pl - A complete and completely relocatable 9-line script
use Cwd;
BEGIN { # Script is relocatable. See http://ccobb.net/ptools/
my $cwd = $1 if ( $0 =~ m#^(.*/)?.*# ); chdir( "$cwd/.." );
my($top,$app)=($1,$2) if ( getcwd() =~ m#^(.*)(?=/)/?(.*)#);
$ENV{'PTOOLS_TOPDIR'} = $top; $ENV{'PTOOLS_APPDIR'} = $app;
} #-----------------------------------------------------------
use PTools::Local; # PTools local/global vars/methods
use MyMain::Module; # then your script begins here #
exit( run MyMain::Module() );
For completely 'relocatable' scripts, just add the first seven lines, above, to the very top of a Perl script. Place a copy of PTools::Local in the directory generated in the 'use lib' line and this module will figure out the rest. After this, as long as a relative directory structure is maintained, your Perl scripts and modules can move to other locations without changing a thing.
If you have other, legacy Perl library path(s) to include, you can add them either just above or just below the use PTools::Local line. Above, and it/they will appear between app lib paths and system paths. Below, and it/they will appear at the very top of your @INC paths. (If it's confusing at first, try print PTools::Local-dump('incpaths')> and it will soon become obvious what's happening.)
If you have moved to a pure OO environment, the above nine lines of code is a full and complete example of a script. It just acts as an outer block to initiate the main module for some application.
Note: Using PTools::Local sets the current working directory to the parent of where a given script is located. This is a necessary part of a 'self-locating' Perl script.
See PTools::Local and PTools::Global.
In addition, general documention about the Perl Tools Framework is available at the following URL.
See http://www.ccobb.net/ptools/.
Chris Cobb, <nospamplease@ccobb.net>
Copyright (c) 1997-2007 by Chris Cobb. All rights reserved. This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
